Joint for lighting-fixtures.



M. E. SURFACE. JOINT FOR LIGHTING FIXTURES. APPLICATION HLED JAN. 31. 1916.

1,281,698. 4 Patented Oct. 15,1918.

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%AT% PAEN FEIQE.

MORRIS E. SURFACE, OF DECATUR, ILLINOIS, ASSIGNOR T0 FARIES MANUFACTURING 00., OF DECATUR, ILLINOIS, A CORPORATION OF ILLINOIS.

JOINT FOR LIGHTING-FIXTURES.

Specification of Letters Patent.

Patented Oct. 15, 1918.

Application filed January 31, 1916. Serial No. 75,208.

To all whom it may concern:

Be it known that I, MoRnIs E. SURFACE, a citizen of the United States, residing at Decatur, in the county of Macon and State. of Illinois, have invented a certain new and useful Improvement in Joints for Lighting- Fixtures, of which the following is a specification.

My invention relates to that class of devices which are designed to provide a detent to prevent the rotation of electric light thereby twisting off the wires, and has for its object to provide a simple and inexpensive form of detent, which shall be entirely concealed from view and yet which will invariably prevent the complete rotation of the fixture.

My means of accomplishing the foregoing objects may be more readily understood by having reference to the accompanying drawings, which are hereunto annexed and are a part of this specification, in which:

Figure 1 is a side elevation of my improvement, part of the exterior being broken away to show the construction.

Figs. 2 and 3, are detail views of parts of the device.

Similar reference numerals refer to similar parts throughout the entire description. I As shown in the drawings, my improvement is applied to a tubular member 4, which is adapted to be pivotally secured to an upright light standard, and comprises a shoulder 5, cast or formed on the tubular member or it may be brazed or soldered thereon, if desired.

This shoulder is provided with a laterally extending lug 6. The tubular member is surrounded by a cylindrical sleeve 7 which is slidable upon the tubular member 4. The sleeve is provided with internal threads 8, which are adapted to engage threads 9, out upon a short nipple 10, which is screwed into an elbow 11. This nipple is provided with a lug 12, corresponding to the lug 6, on the shoulder 5. A coil spring 13, is mounted inside of the cylindrical sleeve 7 and serves to exert a pressure tending to push the cylindrical sleeve into the tubular member 4, the spring being mounted between the inturned end 14, of the cylindrical sleeve 7 and the shoulder 5, of the tubular member 4. By screwing the sleeve onto the nipple 10, the spring is compressed. This pushes the end 15, of the tubular member 4, into the nipple until the lug 6, bears against the end 16, of the nipple 10, while the lug 12, bears against the face of the shoulder 5.

It will be obvious to persons skilled in the art from the foregoing description that while the unit comprising the nipple 10, and elbow 11, can be rotated for a considerable portion of a circle, that before it completes the 360 the two lugs will be brought into engagement with each other and further rotation stopped, in this manner effectually and postitively preventing any possibility of turning the nipple 10, or elbow 11, around enough to twist the wires, and thus break them or cause a short circuit. At the same time, I preserve sufiicient flexibility to permit the light to be shifted to various positions, without the least danger owing to the fact that the spring 13 engages a constant pressure upon the threads on the nipple; there is no liability of the cylindrical sleeve becoming unscrewed sufliciently to permit the disengagement of the lugs, and the consequent possibility of rotation of the light with the danger above referred to. At the same time, I avoid the use of set screws and slots which form places for the lodgment of dirt, etc., my whole device presenting a smooth finished exterior. At the same time, when it is desired to disengage it, it is quickly and easily accomplished by compressing the spring enough to relieve the tension on the threads when the sleeve can be easily unscrewed and the parts disassembled.

Having described my invention what I regard as new and desire to secure by Letters Patent is:

In a joint for lighting fixtures, a tube, a sleeve slidably mounted upon said tube, the said sleeve having one of its ends inturned to form a shoulder and having internal threads at the opposite end, a shoulder formed on said tube between its ends, a lug projecting from the said shoulder toward the outer end of the tube, a spring interposed between the shoulder of the tube and the shoulder of the sleeve, an elbow having an externally threaded nipple slidable on the tube and having a lug projecting from its end adapted to coact with the lug on the shoulder of the sleeve to limit the rotary motion of the nipple on the said tube and the longitudinal movement of the nipple on the said tube, and threads on the nipple engaged 10 by the threads of the sleeve for compressing the spring.

In testimony whereof, I have signed the foregoing specification.

MORRIS E. SURFACE.

Copies of this patent may be obtainedifor five; cents each, by addressing the Commissioner of Patents, Washington, D. O. 

